While around 25% of its users are based in the US, the new service is targeting an international audience, in countries where high-proficiency English teachers are scarce.

“Our main goal is to become the most dominant way to teach languages in the world”

“Our main goal is to become the most dominant way to teach languages in the world,” said Luis von Ahn, Duolingo’s co-founder.

“The goal is to provide a personalised learning experience that gives each student and instructor immediate feedback in the classroom. This can free up teachers’ time to concentrate on difficult concepts, answer questions, and assist students falling behind,” he added.

Last year the company teamed up with local governments to run pilot programmes of the service in public schools in Costa Rica and Guatemala. Within a week of its launch this month the service gained 10,000 teacher accounts and 25,000 affiliated student users.

The app allows teachers to track their students’ progress and receive detailed reports through a centralised dashboard. Some schools have also been using the app to test the English proficiency of their English teachers.

Headquartered in Pittsburgh, the Duolingo language-instruction app and software was created by computer scientists at Carnegie Mellon University in 2012. Since its launch the company has gained 70 million users worldwide.

English-speaking app users can choose from French, Dutch, Danish, German, Irish, Italian, Portuguese and Spanish. The app also offers English instruction for speakers of 18 other languages including Russian, Japanese and Polish.

The move into the school sector follows the announcement last year that the company had launched a certification test that aims to create a new standard for language proficiency which the company eventually plans to start charging for.

The test avoids requiring sitters to undertake the test in an official test centre by using a smartphone’s camera and microphone to monitor for any discrepancies.